Rail brake for traveling bridge



May 14, 1957 F. GOLOB RAIL BRAKE FOR TRAVELING BRIDGE 3 Sheets-Sheet 1 Filed Oct. 30, 1951 I 710672 Q7z% 6 W N Q ELEFHLEFHLEFHLEAIHLEFHIFEIFHLIEHW Hi M 1 0 MI I W/ \N E m w May 14, 1957 F. L. GOLOB RAIL BRAKE FOR TRAVELING BRIDGE Filed 001;. 30, 1951 3 Shee'ts-Sheet 2 May 14, 1957 Filed Oct. 30, 1951 F. L. GOLOB RAIL BRAKE FOR TRAVELING BRIDGE Sheets-Sheet 3 United States Patent RAIL BRAKE FOR TRAVELING BRIDGE Frank L. Goloh, Chicago, Ill., assignor to Inland Steel Company, a corporation of Delaware Application October 30, 1951, Serial No. 253,806

1- Claim. (Cl. 188--38)- This invention relates to automatic safety braking systems and more particularly to an automatic braking system adapted to be installed-in a rail mounted materials handling bridge.

Materials handling bridges are commonly used at dockside installations and travel along rails parallel to the dock for transferring bulk cargo such as coal or ore between water vessels and some means of transportation on the dock, usually railway cars. The body of the bridge normally comprises an elongated steel framework extending from the inshore side of the dock out over the water, i. e. perpendicular to its movement along the dock. A traveling crane-is usually provided on this framework which is movable in a direction perpendicular to the travel of the bridge and between a point on the dock and a point out over the water along side the dock. The framework is normally supported on a pair of spaced bifurcated legs which travel on the dock side rails, the inboard leg known as the pier leg and the outboard leg known as the shear leg. The body portion of the bridge may be anywhere from two hundred to six hundred feet long, standing about eighty-five feet high on a base distance at the bottom of the legs of about'siXty feet. From these dimensions it is obvious that the bridge is a rather large and at times unwieldly structure. The bridge is usually mounted at the base of each leg on railway trucks adapted for movement on standard gauge railway tracks. One track usually runs along the dock and parallel thereto near each end of the bridge to accommodate each leg, while other tracks are usually provided between the legs for railway cars or other cargo carriers to pass under the bridge. The bridges are self-propelled along the tracks, usually having electrically driven motor power systems.

Although the bridges are usually relatively stable under average wind conditions in spite of their large size, sudden gusts of wind may cause skewing, i. e. one bifurcated leg, such as the shear leg, may move along its tracks relatively to the pier leg. A bridge may be designed so that one end may shift under the force of wind about 2 about the other end as a center point. However, sudden gusts of wind may cause a bridge to skew beyond this permissible extent. It is essential therefore to provide braking and anchoring means because there is a constant danger that wind conditions may be abnormal. Particularly when the bridge is being moved from one position to another on the dock is the necessity for efficient braking means important, because undesirable skewing takes place more readily when the bridge is moving.

Prior to the present invention a number of different types of braking systems have been employed for materials handling bridges, all of which have had certain disadvantages which the present invention overcomes. Various types of rail clamps have been used as both braking and anchoring means which frictionally engage the sides of a rail. These clamps become inefiicient after a time because their braking area is reduced as the rail surface on which they clamp becomes worn or deformed.

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Furthermore, these clamps have a relatively small friction surface. Because of these limitations on the efficiency of rail clamps, they are not effective in preventing skewing. More positive clamping action over a larger area of surface friction than rail clamps afford is necessary.

Manual blocking means have been employed as a brake for movable bridges, but this system has the disadvantage of requiring additional manpower to put it into operation. Blocks placed against the wheels on a bridge also are subject to'slippage and do not at the same time provide an anchoring means as the present invention does.

The present invention provides an improved form of automatic braking system for materials handling bridges, which also acts as an anchoring means. The above mentioned problems are overcome by the improved braking system through the provision of a larger frictional surface for braking, a novel means for rigidly anchoring the bridge to combat skewing, and automatic means for bringing these features into operation thus obviating the need for manual control.

The invention will be described as related to the embodiment set out in the'accompanying drawings in which:

Fig. l is a fragmentary side elevation of the lower end of one leg of a materials handling bridge showing the automatic braking system of this invention mounted on the leg; Fig. 2 is a top plan view of the form of the invention shown in Fig. 1, without the sections of the bridge leg; Fig. 3 is a top plan view of the improved brake shoe of the present invention; Fig. 4 is a side elevation of the same shoe; Fig. Sis an end view of the shoe; Fig. 6 is a bottom plan View of the improved brake shoe; Fig. 7 is an enlarged cross sectional view of the friction insert for the brakeshoe; Fig. 8 is a bottom plan view of the liner for the friction insert; and Fig. 9 is a vertical cross section of the power unit of the invention taken along the line 99 of Fig. 2.

Referring now to Figs. 1 and 2, the invention comprises generally a frame A on each leg of the bridge (only one leg being illustrated), a flanged beam B tied to the roadbed between the railway tracks which carry the bridge, and a power unit C mounted substantially in the center of the frame A and having means associated therewith for connecting the power unit C to the flanged beam B.

Referring again to Figs. 1 and 2, it will be seen that the frame A is mounted between the lower ends of the bifurcated sections 20 of the leg of a materials handling bridge and includes a plurality of longitudinal beams 21 suspended therebetween. The frame may be secured at each end to the railway trucks 22 which are normally used to support the legs of the bridge. It is contemplated that a separate frame A will be mounted between the bifurcated ends of each leg of a bridge, that is one frame on the pier leg and one frame on the shear leg, so that one braking system will be provided for each leg, as will be more particularly described.

The flanged beam B is tied to the roadbed 30 upon which the bridge is movable, and is placed between the railway tracks 31 on which the bridge trucks 22 ride, as may be seen in Fig. 5. The flanged beam B comprises an upstanding Web 35, a top flange 36 and a bottom flange 37 which is secured to the roadbed. The web 35 is continuous along the length of the railway tracks 31 upon which the bridge is movable, and to this end it should be welded or otherwise constructed without splice bars so that no interference is presented to the operation of this invention.

It may be seen from Figs. 2 and 9 that the power unit C is preferably centrally mounted on the frame A on any suitable form of carriage 40 which may be an integral part of the frame A. The power unit C comprises a 3 motor 41, a worm gear 42 which is constructed as an extension of the main shaft 43 of the motor 41 and connected thereto by a coupling 44. The worm gear is journalled on the carriage 40 by bearings 45'secured to the carriage 40. A vertical spindle 46 is also journalled on the carriage 40 by brackets 47 and carries a crescent gear 48 on its upper extremity adapted to mesh with the worm 42. A cross bar 49 is secured to the lower extremity of vertical spindle 46.

Rotatably mounted upon the frame A at points remote from the power unit C and immediately above flanged beam B, are a plurality of brake shoes 60. The details of construction of the brake shoes 60 may be seen by reference to Figs. 3 through 8. Each brake shoe 60 includes a short vertical shaft 61 which is journalled on bracket 62 secured to the frame A. The shaft 61'is mounted near the center on the elongated body portion 63 of the shoe. The body portion 63 terminates in opposed end faces 64 and is so curved that upon rotation into one position the end faces 64 will each engage an opposite side of web 35 of flanged beam B. Extending outwardly from the body portion 63 is an arm 65 having a universal joint 66 on the outer extremity thereof. Joined to the arm 65 through the joint 66 is one end of rod 67 which has its other end connected to a similar universal joint 68 on one side of cross bar 49 on the vertical spindle 46. Each brake shoe includes linkage similar to that previously described connecting it either directly to cross bar 49 or indirectly through intermediate brake shoes 60 in the line. In this manner a plurality of brake shoes 60 may be rotated simultaneously into engagement with web 35 by rotation of Vertical spindle 46 and cross bar 49.

Each brake shoe 60 is provided with a replaceable friction insert as best seen in Figs. 7 and 8. A plurality of wells 70 are provided in each brake shoe '60 for reception of friction inserts 71. The inserts 71 include a body portion 72 which may be bolted into the shoe 60 as shown at 73. The body portion 72 has a movable shaft 74 secured thereto which is encircled by a comp-ression spring 75 hearing against the inner end of body member 72 and normally holding the body portion 72 outwardly from the bottom of the well 70. The outer end of body portion 72 has secured thereto receiving plate 76 having crimped sides 77 for receiving a replaceable insert 78. The replaceable insert 78 is substantially rectangular and has one edge of its framework projecting beyond the friction surface and with an aperture 79 therein for registration with a similar aperture 80 on receiving plate 76 whereby the replaceable insert 78 may be secured to the receiving plate '76 by an insertion of a cotter pin 81 through the previously mentioned apertures. The main portion of the replaceable insert 78 may be constructed of a material having a high coefficient of friction with steel, such as the material used for automotive brake linings. The friction surface 82 of the replaceable insert 78'is designed to bear against the surface of web 35 of flanged beam B, through the urging of compression spring 75. As shown in the drawings, a plurality of replaceable inserts 78, as previously described,

are preferably used in each brake shoe 60 so that a large surface of friction is provided in each brake shoe.

in the operation of this invention, it is preferred that any suitable automatic control means may be employed to start the motor 41 immediately upon shutting oft" of the electric controller for the main propulsion machinery for the materials handling bridge. The motor 41 will then automatically drive worm 42 which will mesh with crescent gear 48 to rotate vertical spindle 46 and move cross bar 49. Through the rod 67 and other similar linkage connecting each brake shoe 60 to cross bar 49, the brake shoes 60 will then be automatically rotated into position where friction surfaces 82 on replaceable inserts 78 will be caused to bear against both sides of the web at various areas along flanged beam B. This will provide a large surface friction between the web 35 and friction surfaces 82, thus braking further movement of the bridge. A vertical locked engagement is also provided in this manner between bridge and flanged beam B because of the Wrap-around action of the brake shoes 60 about top flange 36.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom.

I claim:

A braking system for a materials handling bridge having a shear leg and a pier leg, each supported upon trucks, traveling upon rails secured to a road bed, said system comprising: a flanged beam having a top flange and a bottom flange connected by a vertical, continuous web, said beam being secured to said road bed parallel to said rails; a frame, carried by at least one of said legs; a plurality of elongated brake shoes secured to said frame immediately above said vertical web and mounted for rotation about a vertical axis, the end portions of said brake shoes cuwing downwardly and around opposite sides of the top flange of said beam and terminating in flat braking surfaces longitudinally spaced along the beam and adjacent opposite sides of said vertical web, and a power unit on said frame, including a motor; a vertical spindle geared to said motor and journalled in said frame, and means connecting said brake shoes to said vertical spindle, whereby rotation of said spindle by said motor moves the braking surfaces on all of said shoes simultaneously into frictional contact with the opposite sides of said vertical web at linear spaced points along the surface thereof.

References Cited in the file of this patent 

